| Abbreviation | Definition |
|---|---|
| MCGR | McGraw |
| MD | My Dog |
| MDK | Meat Devouring Kid |
| MDK | Meek Dumb Kitten |
| MDK | My Dog Ken |
| MDOM | Male Domination |
| ME | Margaret Elizabeth |
| ME | Mary Ellen |
| ME | Miriam Ellen |
| MechTech | Mechanical Technology |
| MEL | Melanie |
| MEL | Melvin |
| MELP | My Eternal Life Partner |
| MERRY | Merry Everyone Red Red Year |
| MEW | Milena Elise Wilson |
| MexiCali | Mexico California |
| MexiCali | Mexico & California |
| MF | Mary Frances |
| MFR | Medium Fluid Rate |
| MG | Marc Graham |